Simulate an FMU

The otfmi simulate function instanciates, initializes and simulates the FMU.

First, retrieve and load the FMU deviation.fmu.

import openturns as ot
import otfmi.example.utility
import matplotlib.pyplot as plt

path_fmu = otfmi.example.utility.get_path_fmu("deviation")
model = otfmi.fmi.load_fmu(path_fmu)

Note

model is a PyFMI object, loaded with otfmi’s overlay.

As such, model.simulate() is a pure PyFMI method.

Use otfmi.fmi.simulate(model) to benefit from otfmi’s overlay.

otfmi simulate function notably eases initializing a FMU, see Initialize an FMU with non-default values.

On top of the initialization keywords, PyFMI simulation keywords can be employed:

result = otfmi.fmi.simulate(
    model,
    start_time=0,  # PyFMI keyword
    final_time=1,  # PyFMI keyword
    initialization_parameters=(["L"], [300]),
)  # otfmi keyword
print("y = %g" % result.final("y"))

Simulation interval    : 0 - 1.0 seconds.
Elapsed simulation time: 0.012610173999973995 seconds.
y = 22.5

We can use these keyword to plot the deviation Y as function of the beam length L:

inputSample = ot.RegularGrid(1.0, 10.0, 10).getValues()

list_output = []
for length in inputSample:
    result = otfmi.fmi.simulate(model, initialization_parameters=(["L"], [length]))
    list_output.append(result.final("y"))
outputSample = ot.Sample([[xx] for xx in list_output])

plt.figure()
plt.plot(inputSample, outputSample)
plt.show()

Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012708358999987013 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012536673999989034 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012481740999987778 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012518397000008008 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012438518999999815 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01245673299996497 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01235009300000911 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012563315000022612 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012434170999995331 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012499133999995138 seconds.

The interest of the higher-level functions are:

- avoid the for loop on the points of the design of experiment,

- automatic formatting of the simulation outputs.